In a Radio Resource Control (RRC) arrangement of a User Equipment (UE) and a Radio Access Network (RAN) of a next generation mobile communications system, upon termination of a UE call, the RRC of the RAN sends a radio bearer (RB) release message to the RRC of the UE to discard radio access bearer (RAB) information for one or more transparent mode (TM) RBs used by the UE to transmit and receive user information. The release message may also instruct the UE to transition to one of a number of lower activity connection states. In some of the lower activity connection states, the UE is only able to send and receive information at the RRC level. In the event that the UE is to send or receive user information again, then it is necessary to re-establish RAB information for one or more new TM RBs for the UE. This requires an exchange of RAB establishment messages to be communicated between the UE and RAN. These messages are wasteful of air interface resources, can lead to interference with other UEs, can create an un-necessary delay in returning the UE to a suitable configuration for sending/receiving user information and can increase the possibility of signalling errors between the UE and the RAN.